Process for coating fabrics



A. THOMA.

PROCESS FOR COATING FABRICS. APPLICATION FILED SEPT. 12. 19mm L346y6l5.

2 SHEETS-SHEET I.

)n I'ITOT. Andr ew h omcl Hys Patented July 13, 1920 A. THOMA.

PROCESS FOR COATING FABRICS. APPLICATION FILED SEPT. I2, 1916.

1,346,61 5. Patented July 13, 1920,

2 SHEETSSHEET 2.- v

Andrew Thoma UNITED STATES PATENT OFFICE. ANDREW THOMA, OF CAMBRIDGE, hIASSACHUSETTS, ASSIGNOR T0 SYDEMAN, OF BOSTON, MASSACHUSETTS.

\ PROCESS FOR COATING FABRICS.

' Specification of Letters Patent.

l'Patented July 13.,l920.

Application filed September 12, 1916. Serial Io. 119,751.

To all whom it may concern:

Be it known that l, Axmuzw .THOMA, a

citizen of the United States. and resident of which the following description, in connec tion with the accompanying drawing, is a specification. like characters on the drawing representing like parts.

This invention relates to improvements in processes for coating fabrics and particularly those which are used in applying waterproof coating of rubber composition to light fabrics which are used for articles of apparel or for tops and covers of vehicles and for like purposes.

In the usual processes of manufacture of waterproof coated fabrics the coating composition or dope in a plastic or dough-like condition is scraped or rolled into the fabric under considerable pressure. In order to ap ply a fine coating it is necessary either to soften the composition so that it will flow rather freely, or to apply the stifi'er composition under heavy pressure. Where fabrics which are thin or not tightly woven are.

coated in this manner'some of the composition will percolate or be forced through the interstices in the fabric and show upon the uncoated side thereby destroying its appearance and finish and rendering it unsuitable for use.in the manufacture of clothing or in other places where the uncoated side of the fabric is exposed to sight.

The principal object of the present invention is to provide a novel process for applying thin coatings to sensitive fabrics with the minimum amount of pressure necessary properly to incorporate the coating composition in the fabric but which will not force any of it'through to the uncoated side.

' This is accomplished by progressively passing the web of fabric across a suitable dope spreading means and sustaining the fabric in contact with the spreading means by the tension upon the web. the thickness of coating being controlled by varying the speed of movement of the fabric and the tension upon the web.

In the illustrative form of apparatus for I drawings and will be performing the process which is disclosed herein the dope spreading means comprises a cylinder and in the operation a thin even smooth layer of the dope is placed upon the surface of the cylinder and transferred im- 1 immediately therefrom to the fabric. The

thickness of the coating is also controlled therefore by thethichess of the layer of dope supplied to and removed from the cylinder.

The features of employing a spreading cylinder, supplying the dope in-the required thickness to the surface of the cylinder,-

transferring the dope immediately while in fresh condition to the fabric from the cylinder, of moving the web'of fabric progressively past the cylinder, of varying the relative speed of the fabric relatively to the cylinder, of maintaining the cylinder and web of fabric in contact by the tension of the web, and of varying the pressure between the web of fabric and the cylinder together with the other features of the invention hereinafter described, enable all the desired advantages to be efficiently secured and a coating of any desired thicknem to be spread evenly, smoothly and perfectly upon the thinnest and most delicate fabrics in a rapid and economical manner.

Vhile various means may be employed to performthe process" another feature of the invention consists in providing-a suitable apparatus particularly adapted successfully and economically to perform I the. various steps in the process.

Other objects of the invention and the nature thereof will more fully appear in the following description and the accompanying pointed out in the an- Ileiied lcilains. f

n t e rawings;

Figure 1 is a side elevation of a machine embodying the preferred form of my invention, I

Fig. Qis a plan view of thosame,

F 3,- is a detail vertical sectional view of the bottom of the dope hopper, the dope applying roller and the means for sustaining the fabric in contact with the dope applying roller by the tension imposed upon the fabric.

In processes of coating heretofore employed the coating composition or dope is used in the form of a plastic-dough-like material wliich is fed from a suitable hopper upon the face of a moving web of fab1'ic and is spread and pressed into the fabric by a roller'or scraper which engages the coating, the fabric usually being rigidly supquently is squeezed through it.

ported in, relation to a spreading roller or scraper by a roller or plate lying directly beneath the spreading ,means. The dope is thus squeezed into the fabric and not infre- T have discovered that by sustaininglthe moving web of fabric against the spreading 7 a rotary -or other traveling spreading member and-may be operated manually or by power, within the spirit and scope of the means by the tension upon thev web,sufii-' cient pressure is provided properly to corporate the coating composition into the fabric without forcing it through the in= terstices thereof, and that by varying the.

- panying drawing comprises a frame having rate of movement of the fabricacross the spreading device or "by varying the tension upon the web, or both, the thickness of the coating upon the fabric and the depth a moving spreading device, preferably." a spreading cylinder having its surface move.

ing at the lineof contact with the fabric inthe direction in which the web of fabric isotraveling, preferably at a different speed so that" it has a rubbing or smoothin' efiect uponthe coating which not only pro uces a surface having an improved appearance and gloss but also tends to condense the coating composition and to force out bubbles which v otherwise would cause pits or pin holes in 40 s 1 the coating. y

The use of a spreading cylinder as thus described enables the coating to be [laid smoothly and evenly on the fabric, and prethe cylinder to the surface of the fabric,

sents one means by which the thinness of the coating may be controlled. In'the referred form of this invention by use 0 an d adjustable gate the dope is fed to the surface of the cylinder so as to lay upon the surface of the cylinder a I coating of any uired thinness and then this coating is trans erred immediately in amost efficient manner from thus laying it upon the fabric while in a fresh condition and in a smooth and even la r..

The fabric is carried immediately after coating to a suitable drying instrumentality and when thoroughly dry is rolled-up for .storag In the economical performance of the the uncoated side of the fabric is amoving actuator, preferably a cloth covered roller which imposes the'tension upon the web and draws it across the spreaderand thence through the field of-a rea ers a transmitting means.

drying instrumentality which preferably applies heatthrough'the uncoated back of the, fabric-so that the surface of the coating is not scared but retains its plastic conditionwhile the volatile constituents of the composition are driven off. 0

' The spreader preferably is actuated in timed relation to the mechanism which moves the web of fabric so that the feeding of the dope upon the fabric and its spreading will remain uniform, and finally the coated fabric may conveniently be rolled up upon a reel actuated from the same power The spreader preferably isprovided with .removably supporting'the shaft 7 of the roll 8-of'uncoated fabric. Thefabric is led from the roll 8 over guide rolls 9 and 10 which .a-relocated upon opposite sides of the fabric is led across or through a drying mechanism which desirably may comprise a series of pipes 11 supportedin notches in plates 12 secured to the girders *3, l and thence, to a-driving drum 13 which is proroe I vided with 'a'cloth or other frictional covei'ing. From the drum 1? the coated cloth is led to a take-up roll 14 upon which the coated cloth is finally wound. 7

The spreading device comprises a hopper having suitable means for delivering a film or sheet of coating composition or dope upon the upper surface of the web of fabric as it is passed beneath the same.

The contact between the dope app ing by pressure due to the tension placed upon the meansand the web of fabric is eifecte web 'ofifabric. To secure this tension the web is supported at-each side-of the dope applying means,,as for example by the rolls 9 and 10 and the fabric is drawn through the machine by suitable means such as the drum 13 so that by reason of the adjustment and position of the parts the web of fabric is sustained against the dope applying means with the required pressure but without any direct support at the area where the dope is directly applied.

The hopper or dope pan and the dope applying means may be of any suitable character to deliver a thin film or sheet of dope upon the fabric. -A convenient mechanism which is illustrated herein comprises a hopper having ends 15, 16 secured to stands 17 suitably mounted upon the girders 3, 4. The ends of the hopper are connected by a tie-rod 18 and a cross bar 19 to give rigidity to the construction. A gate 20 is -slidably mounted in grooves adjacent the lower edges of the hopper ends and cooperates with a cylinder 21 which extends across the machine. This cylinder and gate which constitute the dope applying means in the preferred form of the invention constitute the closure for the receptacle or hopper.

The gate 20 is adjustable toward and from the cylinder 21; A convenient means for adjusting the gate comprises screws 22 ro- 16 thereof. T

tatably secured in lugs 23 depending from said gate, said screws engaging internally screw threaded bosses 24 upon arms 25 depending from the ends 15, 16. Suitable hand wheels 26 may be provided for rotating the screws. A series of plates 27 connected to the cross bar 19 and extending under the gate serve more rigidly to support the gate and prevent 'it from bending during the operation of the machine so that the edge ofv the gate will remain straight and parallel with the surface of the cylinder and thus in sure the feeding opening between the edge of the gate and the surface of the cylinder being maintained throughout its len th accurately of the same width whereby the thinness of the layer of dope fed to the surface of the cylinder will be the same throughout.

In order to provide for coating fabrics of different widths the hopper may be provided withfalse end plates 28 and 29 which conveniently may be mounted upon guide rods 30, slidabl mounted in the ends 15 and he plates 28 and 29 may be adjusted by screws 31 threaded through the ends 15 and 16 respectively and rotatably en gaging at their ends the central portions of the plates 28, 29. Suitable hand wheels may be provided for conveniently rotating the screws 31.

The spreading cylinder 21, which preferably is provided with a knurled or pitted surface, is mounted upon a shaft 32 which is journaled in boxes 33 slidably mounted in ways in the stands 17. The spreading cylinder 21 may be vertically adjusted by screws 34 threaded through the caps 35 of the stand 17 and at their lower ends rotatably engaging the boxes 33, suitable hand wheels being provided for rotating the screws 34.

The side of the gate 20 is provided with a relatively sharp edge 36 adapted to coiiperate with the surface of the cylinder 21 so as to cause theformation of a thin film or sheet of coating on the surface of the cylinder. The gate preferably is so located that its edge 36 is but a short distance from the web of fabric so that the coating composition or dope will be applied to the fabric almost immediately after it leaves the hopper. thereby preventing the loss of any considerable amount of volatile solvent which retains the dope in a plastic condition and thus laying the dope in a thin smooth even sheet on the fabric while in fresh condition.

As before stated the fabric is sustained in engagement with the spreading device. which in the present i'nsta'nce is the cylinder 21, by the tension upon the web: and the thickness of the coating is controlled by varying the opening of the gate and thus the thickness of the dope on the surface of the cylinder, by varying the rate of movement of the fabric. and by varying the pressure between the spreading-roller and the surface of the fabric. It will be obvious that by varying the thickness of the dope which is supplied to the surface of the cylinder at greater or less thickness of dope may be transferred by the roll to the traveling web of fabric. By increasing the relative speed of the fabric to that of the surface of the roll the film of dope thus applied to the web will be caused to be spread over a greater area and consequently will form a thinner coating upon the fabric, furthermore by increasing the tension upon the web the film of dope thus applied to the fabric by the roll will be spread over a still greater area and a still thinner coating formed. This pressure may be adjusted by raising or lowering the cylinder 21 relatively to the guide rollers 9, 10 or by raising and lowering the guide rollers relatively to the cylinder'21 which may be retained in fixed position. Both adjustments are illustrated in the accompanying drawing, the adjustment of the cylinder 21 having been described. v

The shafts 37, 38 of the gulde rolls 9. 10 are journaled in boxes 39, 40 which are mounted in suitable guideways. These g'uideways may conveniently be formed by facihgofi sufficiently the ends of the base of the stand 17 and providing grooves 42. 43

therein to receive ribs upon the boxes '39 40. the opposite sides of the boxes being guided in grooves 44, 45 formed in brackets 46. 47 suitably secured to the girders 3. 4. Adjusting screws 48 threaded through screw threaded apertures in the girders 3 and 4 and engaging respectively the bottoms of the boxes 39 and 40 serve to adjust the rollers 9 and 10 vertically, and locking nuts 49 carried respectively by the screws 48 and adapted to be jammed against the girders serve to retain the rollers in adjusted position.

By this construction either of the guide rollers 9 or 10 may be adjusted vertically so that with the adjustability of the spreading cylinder'21 a sufliciently widevariation or adjustment may be made to obtain any desired amount orcharacter of pressure between the fabric and the cylinder 21. Thus the fabric maybe run across the guide-rollerssubstantially tangential to the c linder coating upon the fabric the spreading cylin- 21 in which case the spreading cylin er will press very lightly upon the surface of the der 21 desirably is rotated in such a manner that its surface shall travel in the direction of movement'of the fabric at its line of contact therewith but at a different speed, so

as to cause a spreading of the dope over a more extended'area of the fabric and also to force the material into the surface of the fabric. To insure uniformity in the coating the relative speeds of travel of the fabric and of the surface of the spreading cylindershould be maintained uniform. In order to accomplish this purpose the drum 13 which advances the fabric may conveniently be driven from the shaft which rotates the surface of the cylinder 21 in such amanner cylinder 21.

As illustratedherein power is applied to the shaft 32 of the cylinder 21 by a pulley 50 secured to the end of the shaft 32, and a sprocket51 fixed upon the shaft 32 serves to transmit power through a sprocket chain 52 to a sprocket wheel 53 mounted upon a stub shaft 54/journaled in bearings carried by the girder 4. The shaft 54 is provided with a series of gears 55, 56 and .57 adapted respectively toengage cooperating gears 58, 59 and 60 which are slidably feathered upon the shaft 61 of the drum 13. A suitable shifting mechanism such as a lever 62 mounted upon a bracket63 on the end post 2 and having a yoke 64 engaging the common hub of the gears 58, 59 and 60 may serve to place any one of said gears into mesh with its cooperating driving gear 55,

By thus shifting the gears the speed of movement of the fabric may be varied relative to the constant speed of the spreading cylinder 21 so that the dope which is applied by the cylinder may be distributed over a greater or less area according to the relative speeds of movement of the contact- 1ng surfaces of the web of fabric and the spreading cylinder. This system of change speed gearing is to be understood, however, simply as illustrative of a means for adjust- ,i ng therelatiye speed of the fabric andcylthe well known double textures be driven from the shaft 61 of the drum 13 through a pulley 62 secured to the shaft 61 of said drum and driving a belt 63 which passes over a pulley 64' upon the shaft 65 of. the tension roller 14. The belt 63 engages the pulley 64 in. slipping contact so that the coated fabric will be properly wound upon the take-up roll and the action of the drum insured. The. desired tension upon the belt is regulated as by aguide roller 66 carried by brackets 67 secured inangular adjust-' ment to the posts 2.

In the operation of the-machine dope of the proper consistency is placed in the hopper and a web of uncoated fabric drawn from the roll 8'over the guide roll 9 beneath the spreading cylinder 21, over the if guide roller 10, thence over the heating pipes 11 and drum 13 to the take-up roll 14. ower is then applied to the pulley 50 upon the shaft 32 of the cylinder, rotating the same so that its lower portion moves in the direction of the travel of the fabric. The web of fabric 'is driven by the cloth covered drum 13, through the gearing above described, at the desired rate of speed relatively to the speed of rotation of the spreadin cylinder 21.

he gate'20 is adjusted relatively to the as'to deliver a sheet of dope of a predetermined thickness upon the surface of the roller which carries the same into contact with the fabric, spreads it upon the fabric, condenses the coating thus applied and smoothes the same by itswiping contact so that a desirable finish is produced. The

coated. fabric thereupon passes over the drying coils 11 with the back or uncoated side of the fabric toward the coils so that the heat is appliedthrough the fabricand back of the coating.

By this method also a light coating may be applied to the fabric to prepare it for receiving a heavier coating after the first has been allowed to dry and set. In such case thegently applied thin coating will act as a sizing to prevent the heavier coatings from striking through the fabric. If desired the texture thus lightly coated may be applied to heavier coated fabrics to form of Mack intosh cloths. a It will be understood that the particular embodiment of the invention dis closed herein is'illustrative and not restrictive and that various other means may be utilized in the performance of the recess claimed herein, and that various-m cations may be made in the structure of the apparatus within the meaning and scope of the following claims.

ness, progressively moving a web of the fabric across said spreading device and sustaining said web in contact with the spreading device by the tension upon the web.

2. The process of coating fabric which comprises supplying a dope spreading device having a-moving surface with a film of dope of predetermined thickness, progressively moving a web of" fabric across the moving surface of said spreading device and sustaining the web of fabric in contact with the spreading device by the tension upon the web.

.3. The process of coating fabric which comprises su plying a dope spreading cylinmeans of the tension upon the web.

4;, The process of coating fabric which comprises supplying a dope spreading cylinder with a film of dope of redetermined thickness, progressively mov ng a web of fabric across said spreading cylinder and sustaining the 'web in contact with a segment of the surface of said cylinder by means of the tension upon the web and varying the thickness of coating by varying der with a I fabric across said the thickness of dope applied to the surface of the cylinder.

5. The process of coating fabric which comprises su plying a dope spreading cylinder with a 1m of dope of predetermined thickness, progressively moving a web of fabric across said spreading cylinder and sustaining the web inc'ontact with .a' segment of the surface .of said cylinder by means of the tension upon the web and varying the thickness of the coating byva the speed of movement of the web offab'rie.v

6. heprocess of coating fabric which comprises supplying a dope spreading cylinof dope of predetermined thickness, progressively moving a' web of reading cylinder and sustaining the web in contact with a segment of the surface of said c linder by means of the tension upon the we and varying the thickness of the coating by varying the speed of movement of the web of'fabric and the tension upon the web.,

7. The process of coating fabric which comprises supplyingthe moving surface 0 a dope spreading cylinder with a film of dope of predetermined thickness, progressively mo vin I a web of fabric across said spreading cyhnder 'at a different speed than device the peripheral speed of said cylinder and sustaining the webin contact with a segment of the surface of said cylinder by means of the tension upon the we 8. The process of coating fabric which comprises supplying the moving surface of a dope sprea in'g cylinder with a film of dope of predetermined thickness, progresrelatively to the peripheral speed of saidcylinder.

9. The process of coating fabrics which comprises sup 1" a'rotatln do es reading cylinder it li film of p lasti z dgpe of predetermined thickness, and progressively moving a web of fabric across the dope spreading cylinder;

10. A process of coating fabric which comprises progressively moving the fabric across a do'pe' spreading device provided with a rotary dope applying cylinder having its surface at the line of contact rotating in the direction of movement of the web, sustaining the-fabric in contact with the cylinder by the tension on the web and regulating the thickness of coating by varying the relative speed of the contacting surfaces of the cylinder and web.

11. A process of coating fabric which comprises progressively moving the fabric across a dope spreading device provided with a rotary dope applying cylinder having its surface at the line of contact rotating in the direction of movement of the web, sustaining the fabric in contact with the cylin der by the tension ,of the web and regulating the thickness of the coating'by varying the relative speed of the contacting surface of the cylinder and web and the tension upon the web. 12. A process of coating fabric which comprises progressively moving the web of.

fabric across and in contact with a rotary dope applying cylinder, maintaining the linear-speed of the web at a predetermined.

peripheral speed of the e surface of the cylinfrom the cylinder to the web of fabric and. 'during transfer will be thinned out to a pref determined extent.

13. A process of coating fabric which comprises progressively moving the web of fabric across-and in contact with a rotary dope applying cylinder, maintaining the redetermined linear speed of the web at a predetermined higher rate than the peripheral speed of thecylinder, supplyin the surface of the cylinder with a film o dope of redetermined thickness in advance of the initial line of tcteclt whereby the thickness of the coating applied to the Web is regulated by the thickness of 11 the film applied to the cylinder and the relative speed of the web and cylinder.

In testimony whereof, I have signed my name to this specification.

ANDREW THOMA. 

